From patchwork Wed May 31 04:02:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 101215 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp2626168vqr; Tue, 30 May 2023 21:12:48 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6tKBDFy6xTaahqpZ1GRktWrkmMczmzjl9mjknd0TAhLiVo2BR3TdbM3o0VE5qjP4BO7QU6 X-Received: by 2002:a05:622a:1190:b0:3f4:c25f:899 with SMTP id m16-20020a05622a119000b003f4c25f0899mr3787043qtk.68.1685506368674; Tue, 30 May 2023 21:12:48 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1685506368; cv=none; d=google.com; s=arc-20160816; b=j8HI5kzZo/ICWYIeSqznUxO7xe8jX2a6fo9y8Xq97inmgw3k0hwWnHPJz7vQ5BX8J9 CzjmRyCp2eqqm1hcduKp2wEE0IR/hkBkuYjnb6Vyi/3CM5uLkw4XCF3wICFxvdYufJqQ Gmshj/TK/VknxqB++ybMBqSLNwZTPtfdrhaOeL+JETcD0kDVFTvFGeIibu7sMv0hRJxL /HUpwfUDtQ0aPiyYQ6EytuMghU1PdDoj6FekPxxqRApveWn+XmKYssFr12fd4nx2ijGK YKaKDA6m4THj0wCA7BCBnyzHv3bpYwQbHXN1P58RPu5f7CM5c2pCNz0eZK8+UEyO4JOd /FIA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:mime-version:date :dkim-signature; bh=FRShDzU+m20ot9o4O+80g75qyx0AzeQfhVYqf4ZY7r8=; b=ZrQfs+HN4tHdifjlKu303jDOlWCOSCpKbhBj+4fXCWT1Zt2ikqnYnS2zYuA+QUYg9h o/LZKGn/8fHVG6EKc9IYvkGKvO+/uMtU2DB4mhtBhpMckh6Io2widbXfTsx6NR/zJBGQ Gh71avYi18A8bc9r5xmdChmgb3iLDxXWBGMHhA+8raCnJJ3ppo7j1WUnRBAb7pIWJUVC yEOTOAVHguzOMECehLxSnOiYHdOtvwYZRZn/UqRDhfYCql+9qfy5PoleenelCknqAASy +5FqYZx5L8o/FdDQ3IzKRW8TV8OhmLbW5ZVktkwxHSyEgKuA6WtqsUi1NZl6V+MjNewB Fe9A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=Ql0coGq1; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id nr2-20020a17090b240200b00233e301c780si304081pjb.31.2023.05.30.21.12.36; Tue, 30 May 2023 21:12:48 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=Ql0coGq1; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234066AbjEaECO (ORCPT + 99 others); Wed, 31 May 2023 00:02:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230095AbjEaECJ (ORCPT ); Wed, 31 May 2023 00:02:09 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06A84107 for ; Tue, 30 May 2023 21:02:08 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-bad1c8dce48so8911805276.0 for ; Tue, 30 May 2023 21:02:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685505727; x=1688097727; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=FRShDzU+m20ot9o4O+80g75qyx0AzeQfhVYqf4ZY7r8=; b=Ql0coGq15Pj7nTlxZq2f/RivqyjWmPolPYZ2HZFcuekbbm33jfO2dDe82WO2v1/qbk /0rAWbwAhOEAeLqo+DBjfOUetbwAHYSr6SCT7UNmRnoKrZhODAzGy6rozWxzB0GFfoeK LDoujjTAbvrWNyIgH5c/Pg613GMixADgkWZf5GXNLKoofc9DJ5AkH5wzAL4ppeN/yd+t jXSLlKA9RdamVar9TI4EUuLsUSNbXVZbkRRlZQXHZ5/1cF7c2TQfTlUVFQWn+Knn4T5T b93NBITM+3BHDI02S2hws83FjuuCzNBdhptgbJvPXHSzwhPWaFmO42Jl5l5KXThnr0Xz FRaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685505727; x=1688097727; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=FRShDzU+m20ot9o4O+80g75qyx0AzeQfhVYqf4ZY7r8=; b=aq7SxycBvHJ8IV0kKj7scAeddtrGUUZyEbx3cCcAeqS3rldyCKHA+/R8tXQB9MM5TO bqzwtT7kw4sL3GWFGw4bua+0SmOlkEM1tBOAZtf1jPraS3vDw4fsYLuns3i80P1sZLi1 qVLg69KDd89tVz92o83Z40mCvGuWXrPoZOT4YCy+kvMn7d1/8Hk8eB7AvzNyxwWhGQDp dndpOUl8akjc9ZKjS9evAZmBQB73HKzm/iRvWnm87aAUh2vxiHUYN1TSi+yuq7ery6nv H89E2lfLgQOBIODRVZZraQO/hroQT/CyVpna7iY21zxsnOzY4BeYJ5aVzFfzH0MGFwE7 7Ezw== X-Gm-Message-State: AC+VfDyEVHdQfmU7kBy5SDynjRFxgfOnUY+TRb8xVTRZUnDLwWai1Mly I2KP1PAy0N1XqXWgCP5SgpsFaSdiLqM= X-Received: from badhri.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:6442]) (user=badhri job=sendgmr) by 2002:a5b:14f:0:b0:bac:faf4:78fd with SMTP id c15-20020a5b014f000000b00bacfaf478fdmr1794911ybp.7.1685505727275; Tue, 30 May 2023 21:02:07 -0700 (PDT) Date: Wed, 31 May 2023 04:02:01 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230531040203.19295-1-badhri@google.com> Subject: [PATCH v5 1/3] usb: gadget: udc: core: Offload usb_udc_vbus_handler processing From: Badhri Jagan Sridharan To: gregkh@linuxfoundation.org, stern@rowland.harvard.edu, colin.i.king@gmail.com, xuetao09@huawei.com, quic_eserrao@quicinc.com, water.zhangjiantao@huawei.com, peter.chen@freescale.com, balbi@ti.com, francesco@dolcini.it, alistair@alistair23.me, stephan@gerhold.net, bagasdotme@gmail.com, luca@z3ntu.xyz Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Badhri Jagan Sridharan X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1767275890699604667?= X-GMAIL-MSGID: =?utf-8?q?1767381525932249130?= usb_udc_vbus_handler() can be invoked from interrupt context by irq handlers of the gadget drivers, however, usb_udc_connect_control() has to run in non-atomic context due to the following: a. Some of the gadget driver implementations expect the ->pullup callback to be invoked in non-atomic context. b. usb_gadget_disconnect() acquires udc_lock which is a mutex. Hence offload invocation of usb_udc_connect_control() to workqueue. Cc: stable@vger.kernel.org Fixes: 1016fc0c096c ("USB: gadget: Fix obscure lockdep violation for udc_mutex") Signed-off-by: Badhri Jagan Sridharan --- Changes since v1: - Address Alan Stern's comment on usb_udc_vbus_handler invocation from atomic context: * vbus_events_lock is now a spinlock and allocations in * usb_udc_vbus_handler are atomic now. Changes since v2: - Addressing Alan Stern's comments: ** connect_lock is now held by callers of * usb_gadget_pullup_update_locked() and gadget_(un)bind_driver() does * notdirectly hold the lock. ** Both usb_gadget_(dis)connect() and usb_udc_vbus_handler() would * set/clear udc->vbus and invoke usb_gadget_pullup_update_locked. ** Add "unbinding" to prevent new connections after the gadget is being * unbound. Changes since v3: ** Made a minor cleanup which I missed to do in v3 in * usb_udc_vbus_handler(). Changes since v4: - Addressing Alan Stern's comments: ** usb_udc_vbus_handler() now offloads invocation of usb_udc_connect_control() * from workqueue. ** Dropped vbus_events list as this was redundant. Updating to the * latest value is suffice --- drivers/usb/gadget/udc/core.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) base-commit: 046895105d9666ab56e86ce8dd9786f8003125c6 diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 52e6d2e84e35..44a9f32679b5 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -48,6 +48,7 @@ struct usb_udc { struct list_head list; bool vbus; bool started; + struct work_struct vbus_work; }; static struct class *udc_class; @@ -1086,6 +1087,13 @@ static void usb_udc_connect_control(struct usb_udc *udc) usb_gadget_disconnect(udc->gadget); } +static void vbus_event_work(struct work_struct *work) +{ + struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work); + + usb_udc_connect_control(udc); +} + /** * usb_udc_vbus_handler - updates the udc core vbus status, and try to * connect or disconnect gadget @@ -1094,6 +1102,13 @@ static void usb_udc_connect_control(struct usb_udc *udc) * * The udc driver calls it when it wants to connect or disconnect gadget * according to vbus status. + * + * This function can be invoked from interrupt context by irq handlers of the gadget drivers, + * however, usb_udc_connect_control() has to run in non-atomic context due to the following: + * a. Some of the gadget driver implementations expect the ->pullup callback to be invoked in + * non-atomic context. + * b. usb_gadget_disconnect() acquires udc_lock which is a mutex. + * Hence offload invocation of usb_udc_connect_control() to workqueue. */ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) { @@ -1101,7 +1116,7 @@ void usb_udc_vbus_handler(struct usb_gadget *gadget, bool status) if (udc) { udc->vbus = status; - usb_udc_connect_control(udc); + schedule_work(&udc->vbus_work); } } EXPORT_SYMBOL_GPL(usb_udc_vbus_handler); @@ -1328,6 +1343,7 @@ int usb_add_gadget(struct usb_gadget *gadget) mutex_lock(&udc_lock); list_add_tail(&udc->list, &udc_list); mutex_unlock(&udc_lock); + INIT_WORK(&udc->vbus_work, vbus_event_work); ret = device_add(&udc->dev); if (ret) @@ -1558,6 +1574,7 @@ static void gadget_unbind_driver(struct device *dev) kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); + cancel_work_sync(&udc->vbus_work); usb_gadget_disconnect(gadget); usb_gadget_disable_async_callbacks(udc); if (gadget->irq) From patchwork Wed May 31 04:02:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 101218 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp2629220vqr; Tue, 30 May 2023 21:22:39 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5hTS6ynAdB4mT25yfTaBd6jrS2/kWFedCQiT0NbLyvjWZZGTtfrcvpuoAMZRva0WXAongv X-Received: by 2002:a05:6a20:7490:b0:10b:7243:c212 with SMTP id p16-20020a056a20749000b0010b7243c212mr5066072pzd.42.1685506958813; Tue, 30 May 2023 21:22:38 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1685506958; cv=none; d=google.com; s=arc-20160816; b=CQL//xsTxFQAwmNfKNwyM5G4CbpY9MfKP/l+jly+qs+8e41dnCbQFFqkg1K6OeTkfT 0hhZuqgSl1AbIuL4S/eSEWQww6YuW0OTxl8bSSuEJUotCaTa22bKvWHInI/ezm/L/Pj5 HlCri+XTtInUqSfs0uyXLDWqklPbuLCCSy5BOtOfQfH0c5RSDYI81LSSJ4mn9QlnHRaZ 9c/DRd62Jro13Y9cbrLV876z4W+lrl/v4abIRdAGrdPTDXYKT00EFq5Kvxv60I9rf//x JGN0COcpZWZlRAAjS6TTiTCyKhjMQq9HH0dRgoJoSQ485AtqzSue+qG/Li2gspPpmItq mFyw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:dkim-signature; bh=v6QTveAwLS+RXrF0pN6prG1FOlU7FfJOhesY8AMEUQ4=; b=tGT/ERAW47y3v8yc9aBMVFb8Bzwl4je77o8OD3E4neP2HDi7QvTcWu2wz/Fj45BJDq vvZ2nS0GtmjisSGr0fasd1fRxVtA5PEHt33MueALxcq7CmT+CrPxaNOl0a6xf2u4cMCZ L98SVvd5m6XmaLjen+kCMzKMaKgAqmrgaBghcjeTecJsLgi2xUK+oZQyYPYTBrcdh2Jy 4XHpkHcQa1ZF7/Yv/jKYQ3+yTcvgPDibM6FmeR7nM8X2sJ0JYZpUK3NRoehEEpFxfEm7 k/Yg+Q5nOb7tWUYoRw9CB2cvwFG/vUGrFrLnwZkGjOoA0yimMELS+VVBzsxE4Z79+6Bg ddZA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=RTjAikjK; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from out1.vger.email (out1.vger.email. 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This causes gadget->ops->pullup to be called through usb_gadget_connect() when invoked from usb_udc_vbus_handler() even before usb_gadget_udc_start() is called. Guard this by checking for udc->started in usb_udc_connect_control() before invoking usb_gadget_connect(). Guarding udc->vbus, udc->started, gadget->connect, gadget->deactivate related functions with connect_lock. usb_gadget_connect_locked(), usb_gadget_disconnect_locked(), usb_udc_connect_control_locked(), usb_gadget_udc_start_locked(), usb_gadget_udc_stop_locked() are called with this lock held as they can be simulataneously invoked from different code paths. Adding an additional check to make sure udc is started(udc->started) before pullup callback is invoked. This commit was reverted due to the crash reported in https://lore.kernel.org/all/ZF4BvgsOyoKxdPFF@francesco-nb.int.toradex.com/. commit 16737e78d190 ("usb: gadget: udc: core: Offload usb_udc_vbus_handler processing") addresses the crash reported. Cc: stable@vger.kernel.org Fixes: 628ef0d273a6 ("usb: udc: add usb_udc_vbus_handler") Signed-off-by: Badhri Jagan Sridharan --- v5 is the first version in this series. --- drivers/usb/gadget/udc/core.c | 148 ++++++++++++++++++++++++---------- 1 file changed, 104 insertions(+), 44 deletions(-) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 44a9f32679b5..6ffe5fda8bb7 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -37,6 +37,10 @@ static const struct bus_type gadget_bus_type; * @vbus: for udcs who care about vbus status, this value is real vbus status; * for udcs who do not care about vbus status, this value is always true * @started: the UDC's started state. True if the UDC had started. + * @connect_lock: protects udc->vbus, udc->started, gadget->connect, gadget->deactivate related + * functions. usb_gadget_connect_locked, usb_gadget_disconnect_locked, + * usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are + * called with this lock held. * * This represents the internal data structure which is used by the UDC-class * to hold information about udc driver and gadget together. @@ -49,6 +53,7 @@ struct usb_udc { bool vbus; bool started; struct work_struct vbus_work; + struct mutex connect_lock; }; static struct class *udc_class; @@ -688,17 +693,9 @@ int usb_gadget_vbus_disconnect(struct usb_gadget *gadget) } EXPORT_SYMBOL_GPL(usb_gadget_vbus_disconnect); -/** - * usb_gadget_connect - software-controlled connect to USB host - * @gadget:the peripheral being connected - * - * Enables the D+ (or potentially D-) pullup. The host will start - * enumerating this gadget when the pullup is active and a VBUS session - * is active (the link is powered). - * - * Returns zero on success, else negative errno. - */ -int usb_gadget_connect(struct usb_gadget *gadget) +/* Internal version of usb_gadget_connect needs to be called with connect_lock held. */ +static int usb_gadget_connect_locked(struct usb_gadget *gadget) + __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -707,10 +704,12 @@ int usb_gadget_connect(struct usb_gadget *gadget) goto out; } - if (gadget->deactivated) { + if (gadget->deactivated || !gadget->udc->started) { /* * If gadget is deactivated we only save new state. * Gadget will be connected automatically after activation. + * + * udc first needs to be started before gadget can be pulled up. */ gadget->connected = true; goto out; @@ -725,22 +724,32 @@ int usb_gadget_connect(struct usb_gadget *gadget) return ret; } -EXPORT_SYMBOL_GPL(usb_gadget_connect); /** - * usb_gadget_disconnect - software-controlled disconnect from USB host - * @gadget:the peripheral being disconnected - * - * Disables the D+ (or potentially D-) pullup, which the host may see - * as a disconnect (when a VBUS session is active). Not all systems - * support software pullup controls. + * usb_gadget_connect - software-controlled connect to USB host + * @gadget:the peripheral being connected * - * Following a successful disconnect, invoke the ->disconnect() callback - * for the current gadget driver so that UDC drivers don't need to. + * Enables the D+ (or potentially D-) pullup. The host will start + * enumerating this gadget when the pullup is active and a VBUS session + * is active (the link is powered). * * Returns zero on success, else negative errno. */ -int usb_gadget_disconnect(struct usb_gadget *gadget) +int usb_gadget_connect(struct usb_gadget *gadget) +{ + int ret; + + mutex_lock(&gadget->udc->connect_lock); + ret = usb_gadget_connect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(usb_gadget_connect); + +/* Internal version of usb_gadget_disconnect needs to be called with connect_lock held. */ +static int usb_gadget_disconnect_locked(struct usb_gadget *gadget) + __must_hold(&gadget->udc->connect_lock) { int ret = 0; @@ -752,10 +761,12 @@ int usb_gadget_disconnect(struct usb_gadget *gadget) if (!gadget->connected) goto out; - if (gadget->deactivated) { + if (gadget->deactivated || !gadget->udc->started) { /* * If gadget is deactivated we only save new state. * Gadget will stay disconnected after activation. + * + * udc should have been started before gadget being pulled down. */ gadget->connected = false; goto out; @@ -775,6 +786,30 @@ int usb_gadget_disconnect(struct usb_gadget *gadget) return ret; } + +/** + * usb_gadget_disconnect - software-controlled disconnect from USB host + * @gadget:the peripheral being disconnected + * + * Disables the D+ (or potentially D-) pullup, which the host may see + * as a disconnect (when a VBUS session is active). Not all systems + * support software pullup controls. + * + * Following a successful disconnect, invoke the ->disconnect() callback + * for the current gadget driver so that UDC drivers don't need to. + * + * Returns zero on success, else negative errno. + */ +int usb_gadget_disconnect(struct usb_gadget *gadget) +{ + int ret; + + mutex_lock(&gadget->udc->connect_lock); + ret = usb_gadget_disconnect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); + + return ret; +} EXPORT_SYMBOL_GPL(usb_gadget_disconnect); /** @@ -795,10 +830,11 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) if (gadget->deactivated) goto out; + mutex_lock(&gadget->udc->connect_lock); if (gadget->connected) { - ret = usb_gadget_disconnect(gadget); + ret = usb_gadget_disconnect_locked(gadget); if (ret) - goto out; + goto unlock; /* * If gadget was being connected before deactivation, we want @@ -808,6 +844,8 @@ int usb_gadget_deactivate(struct usb_gadget *gadget) } gadget->deactivated = true; +unlock: + mutex_unlock(&gadget->udc->connect_lock); out: trace_usb_gadget_deactivate(gadget, ret); @@ -831,6 +869,7 @@ int usb_gadget_activate(struct usb_gadget *gadget) if (!gadget->deactivated) goto out; + mutex_lock(&gadget->udc->connect_lock); gadget->deactivated = false; /* @@ -838,7 +877,8 @@ int usb_gadget_activate(struct usb_gadget *gadget) * while it was being deactivated, we call usb_gadget_connect(). */ if (gadget->connected) - ret = usb_gadget_connect(gadget); + ret = usb_gadget_connect_locked(gadget); + mutex_unlock(&gadget->udc->connect_lock); out: trace_usb_gadget_activate(gadget, ret); @@ -1079,19 +1119,22 @@ EXPORT_SYMBOL_GPL(usb_gadget_set_state); /* ------------------------------------------------------------------------- */ -static void usb_udc_connect_control(struct usb_udc *udc) +/* Acquire connect_lock before calling this function. */ +static void usb_udc_connect_control_locked(struct usb_udc *udc) __must_hold(&udc->connect_lock) { - if (udc->vbus) - usb_gadget_connect(udc->gadget); + if (udc->vbus && udc->started) + usb_gadget_connect_locked(udc->gadget); else - usb_gadget_disconnect(udc->gadget); + usb_gadget_disconnect_locked(udc->gadget); } static void vbus_event_work(struct work_struct *work) { struct usb_udc *udc = container_of(work, struct usb_udc, vbus_work); - usb_udc_connect_control(udc); + mutex_lock(&udc->connect_lock); + usb_udc_connect_control_locked(udc); + mutex_unlock(&udc->connect_lock); } /** @@ -1139,7 +1182,7 @@ void usb_gadget_udc_reset(struct usb_gadget *gadget, EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); /** - * usb_gadget_udc_start - tells usb device controller to start up + * usb_gadget_udc_start_locked - tells usb device controller to start up * @udc: The UDC to be started * * This call is issued by the UDC Class driver when it's about @@ -1150,8 +1193,11 @@ EXPORT_SYMBOL_GPL(usb_gadget_udc_reset); * necessary to have it powered on. * * Returns zero on success, else negative errno. + * + * Caller should acquire connect_lock before invoking this function. */ -static inline int usb_gadget_udc_start(struct usb_udc *udc) +static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) + __must_hold(&udc->connect_lock) { int ret; @@ -1168,7 +1214,7 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) } /** - * usb_gadget_udc_stop - tells usb device controller we don't need it anymore + * usb_gadget_udc_stop_locked - tells usb device controller we don't need it anymore * @udc: The UDC to be stopped * * This call is issued by the UDC Class driver after calling @@ -1177,8 +1223,11 @@ static inline int usb_gadget_udc_start(struct usb_udc *udc) * The details are implementation specific, but it can go as * far as powering off UDC completely and disable its data * line pullups. + * + * Caller should acquire connect lock before invoking this function. */ -static inline void usb_gadget_udc_stop(struct usb_udc *udc) +static inline void usb_gadget_udc_stop_locked(struct usb_udc *udc) + __must_hold(&udc->connect_lock) { if (!udc->started) { dev_err(&udc->dev, "UDC had already stopped\n"); @@ -1337,6 +1386,7 @@ int usb_add_gadget(struct usb_gadget *gadget) udc->gadget = gadget; gadget->udc = udc; + mutex_init(&udc->connect_lock); udc->started = false; @@ -1539,11 +1589,15 @@ static int gadget_bind_driver(struct device *dev) if (ret) goto err_bind; - ret = usb_gadget_udc_start(udc); - if (ret) + mutex_lock(&udc->connect_lock); + ret = usb_gadget_udc_start_locked(udc); + if (ret) { + mutex_unlock(&udc->connect_lock); goto err_start; + } usb_gadget_enable_async_callbacks(udc); - usb_udc_connect_control(udc); + usb_udc_connect_control_locked(udc); + mutex_unlock(&udc->connect_lock); kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); return 0; @@ -1575,12 +1629,14 @@ static void gadget_unbind_driver(struct device *dev) kobject_uevent(&udc->dev.kobj, KOBJ_CHANGE); cancel_work_sync(&udc->vbus_work); - usb_gadget_disconnect(gadget); + mutex_lock(&udc->connect_lock); + usb_gadget_disconnect_locked(gadget); usb_gadget_disable_async_callbacks(udc); if (gadget->irq) synchronize_irq(gadget->irq); udc->driver->unbind(gadget); - usb_gadget_udc_stop(udc); + usb_gadget_udc_stop_locked(udc); + mutex_unlock(&udc->connect_lock); mutex_lock(&udc_lock); driver->is_bound = false; @@ -1666,11 +1722,15 @@ static ssize_t soft_connect_store(struct device *dev, } if (sysfs_streq(buf, "connect")) { - usb_gadget_udc_start(udc); - usb_gadget_connect(udc->gadget); + mutex_lock(&udc->connect_lock); + usb_gadget_udc_start_locked(udc); + usb_gadget_connect_locked(udc->gadget); + mutex_unlock(&udc->connect_lock); } else if (sysfs_streq(buf, "disconnect")) { - usb_gadget_disconnect(udc->gadget); - usb_gadget_udc_stop(udc); + mutex_lock(&udc->connect_lock); + usb_gadget_disconnect_locked(udc->gadget); + usb_gadget_udc_stop_locked(udc); + mutex_unlock(&udc->connect_lock); } else { dev_err(dev, "unsupported command '%s'\n", buf); ret = -EINVAL; From patchwork Wed May 31 04:02:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Badhri Jagan Sridharan X-Patchwork-Id: 101222 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp2630328vqr; 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The new flag "allow_start" is now set by gadget_bind_driver() and cleared by gadget_unbind_driver(). usb_gadget_udc_start_locked() now checks whether allow_start is set before starting the UDC by invoking the ->udc_start() callback. Fixes: fc274c1e9973 ("USB: gadget: Add a new bus for gadgets") Cc: stable Signed-off-by: Badhri Jagan Sridharan --- v5 is the first version in this series. --- drivers/usb/gadget/udc/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index 6ffe5fda8bb7..ac9d6186815d 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -37,6 +37,8 @@ static const struct bus_type gadget_bus_type; * @vbus: for udcs who care about vbus status, this value is real vbus status; * for udcs who do not care about vbus status, this value is always true * @started: the UDC's started state. True if the UDC had started. + * @allow_start: Indicates whether UDC is allowed to start. Set/cleared by gadget_(un)bind_driver() + * after gadget driver is bound or unbound. * @connect_lock: protects udc->vbus, udc->started, gadget->connect, gadget->deactivate related * functions. usb_gadget_connect_locked, usb_gadget_disconnect_locked, * usb_udc_connect_control_locked, usb_gadget_udc_start_locked, usb_gadget_udc_stop_locked are @@ -52,6 +54,7 @@ struct usb_udc { struct list_head list; bool vbus; bool started; + bool allow_start; struct work_struct vbus_work; struct mutex connect_lock; }; @@ -1204,6 +1207,9 @@ static inline int usb_gadget_udc_start_locked(struct usb_udc *udc) if (udc->started) { dev_err(&udc->dev, "UDC had already started\n"); return -EBUSY; + } else if (!udc->allow_start) { + dev_err(&udc->dev, "UDC not allowed to start. Is gadget driver bound ?\n"); + return -EIO; } ret = udc->gadget->ops->udc_start(udc->gadget, udc->driver); @@ -1590,6 +1596,7 @@ static int gadget_bind_driver(struct device *dev) goto err_bind; mutex_lock(&udc->connect_lock); + udc->allow_start = true; ret = usb_gadget_udc_start_locked(udc); if (ret) { mutex_unlock(&udc->connect_lock); @@ -1630,6 +1637,7 @@ static void gadget_unbind_driver(struct device *dev) cancel_work_sync(&udc->vbus_work); mutex_lock(&udc->connect_lock); + udc->allow_start = false; usb_gadget_disconnect_locked(gadget); usb_gadget_disable_async_callbacks(udc); if (gadget->irq)